Influence of Complex Loading Conditions on Intervertebral Disc Failure
Influence of Complex Loading Conditions on Intervertebral Disc Failure
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DOI：
10.1097/brs.0000000000001699
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发表时间：
2017-01-15
期刊：
影响因子：
3
通讯作者：
Wilke, Hans-Joachim
中科院分区：
文献类型：
--
作者：
Berger-Roscher, Nikolaus;Casaroli, Gloria;Wilke, Hans-Joachim
研究设计.高分辨率成像研究绵羊腰椎间盘在复杂载荷下的破坏。研究不同的载荷组合如何影响椎间盘破坏的机制和程度。尽管对椎间盘在各种条件下如何失败进行了广泛的研究，但失败的机制仍然不清楚。此外，在复杂载荷作用下，不同加载方向对破坏模式和破坏程度的影响从未得到系统的研究。在新开发的动态6自由度（6-DOF）椎间盘载荷模拟器中，在以下载荷参数的5种组合下对30个绵羊腰椎节段进行载荷：0 °-13 °屈曲、0 °-10 °侧弯、0 °-4 °轴向旋转、0 - 800 N轴向压缩。在2 Hz下共进行了1000次循环。测试后，在超高场磁共振成像（11.7 T）扫描仪和微型计算机断层扫描仪中进行椎间盘成像。共发生13例大终板连接失败（EPJF），除1例外，其余均保持软骨终板完整。13例EPJF中有10例发生在尾部。发生了4例单纯瓣环失效，仅影响外部后瓣环。未观察到疝形成。任何组中测得的最大力矩（中位数）为52.5 N。m屈曲，16.5 N。m的横向弯曲和14.0 N. m轴向旋转。复杂的加载方案可能导致体外EPJF（76%）和瓣环失效（24%）。屈曲、侧弯、轴向旋转和轴向压缩的组合对尾侧EPJF的风险最高。无侧向弯曲的无螺纹接头失效风险最低，反之亦然。轴向压缩和轴向旋转的影响似乎都小于屈曲和侧弯。疝似乎需要软骨终板的额外失效，可能由进一步的轴向压缩载荷引起。
Study Design. High resolution imaging investigation of the failure of ovine lumbar intervertebral discs under complex loading.Objective. To investigate how different loading combinations influence the mechanism and extent of intervertebral disc failure.Summary of Background Data. Even though there has been extensive research on how an intervertebral disc fails under various conditions, failure mechanisms remain unclear. In addition, the influence of different loading directions on the mode and extent of failure under complex loading was never systematically investigated.Methods. Thirty ovine lumbar spinal segments were loaded in a newly developed, dynamic, 6-degree-of-freedom (6-DOF) disc loading simulator under five combinations of the following loading parameters: 0 degrees-13 degrees flexion, 0 degrees-10 degrees lateral bending, 0 degrees-4 degrees axial rotation, 0-800 N axial compression. A total of 1000 cycles at 2 Hz were done. After testing, imaging of the discs was performed in an ultra-high field magnetic resonance imaging (11.7 T) scanner and with a micro-computed tomography scanner.Results. A total of 13 large endplate junction failures (EPJFs) occurred, of which all but one maintained an intact cartilaginous endplate. Ten out of 13 EPJFs occurred caudally. Four solely annulus failures occurred affecting only the outer posterior annulus. A herniation was not observed. The maximum moments measured in any group (median) were 52.5 N . m flexion, 16.5 N . m lateral bending, and 14.0 N . m axial rotation.Conclusion. Complex loading protocols could lead to EPJFs (76%) and annulus failures (24%) in vitro. The combination of flexion, lateral bending, axial rotation, and axial compression bears the highest risk for caudal EPJF. Flexion without lateral bending and vice versa has the lowest risk for failure. Both axial compression and axial rotation seem to have a smaller influence than flexion and lateral bending. It seems that a herniation requires an additional failure of the cartilaginous endplate, likely initiated by further axial compressive load.